A spark gap exists between each pair of electrodes, and the electrode pairs are separated by a dielectric, such as a gas. As an ever increasing potential is applied to the electrodes across the gap, there comes a potential at which a spark will leap across the gap between the electrodes. This potential is known as the striking potential. Spark gaps are used, in particular, as a means for creating an electrical discharge by short circuiting a capacitor in order to excite some kinds of gas laser.
When a particularly large amount of energy is released in the spark, and it is desired to operate the laser at a high repetition rate, a multiple or rail spark gap is used comprising a plurality of pairs of electrodes connected in parallel. This arrangement has the advantage of reducing the discharge impedance and of increasing the sevice life of the electrodes used.
However, such multiple spark gaps suffer from a drawback: although the gap between each pair of electrodes can be individually adjusted, it remains difficult to obtain a simultaneous discharge between all the pairs of electrodes.
Preferred embodiments of the present invention mitigate this drawback.